BIOS (Basic Input Output System) are machine executable binary codes stored in a mainboard's ROM. The machine executable binary codes may include, for example, BIOS program, configuration information, Power-on Self-test, initialization procedure, interrupt services for Operating System and applications which are running, and so on. BIOS control operations of all hardware of a computer system, and provide underlying calls for high-level software.
In order to enable users to control mainboard startup and hardware operations according to their own requirements, BIOS provide a setup (startup setting) interface for users to set startup parameters. When the mainboard is booting, the users may press a key to enter the setup interface to modify the startup parameters in a predetermined time period. At this time, the startup process of the mainboard is interrupted. The mainboard is restarted when the users logged out the setup interface.